Eur. Phys. J. Special Topics 227, 1361–1375 (2018)
https://doi.org/10.1140/epjst/e2018-00069-3

Regular Article

Quasiparticle cooling using a topological insulator–superconductor hybrid junction

¹ Donostia International Physics Center (DIPC), Manuel de Lardizbal 4, 20018 San Sebastián, Spain
² IKERBASQUE, Basque Foundation of Science, 48011 Bilbao, Basque Country, Spain
³ CNR-SPIN, Monte S.Angelo, via Cinthia, 80126 Napoli, Italy
⁴ Dipartimento di Fisica “E. Pancini”, Universitá di Napoli “Federico II”, Monte S. Angelo, 80126 Napoli, Italy

^a e-mail: dario.bercioux@dipc.org

Received: 23 April 2018
Received in final form: 4 June 2018
Published online: 27 July 2018

Abstract

In this work, we investigate the thermoelectric properties of a hybrid junction realised coupling surface states of a three-dimensional topological insulator with a conventional s-wave superconductor. We focus on the ballistic devices and study the quasiparticle flow, carrying both electric and thermal currents, adopting a scattering matrix approach based on conventional Blonder–Tinkham–Klapwijk formalism. We calculate the cooling efficiency of the junction as a function of the microscopic parameters of the normal region (i.e. the chemical potential, etc.). The cooling power increases when moving from a regime of Andreev specular-reflection to a regime where Andreev retro-reflection dominates. Differently from the case of a conventional N/S interface, we can achieve efficient cooling of the normal region, without including any explicit impurity scattering at the interface, to increase normal reflection.